Normalization of equalizer soft output for channels with varying noise power
US6980602B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2001 |
| Grant date | Dec 27, 2005 |
| Priority date | — |
| Expiry date | Oct 26, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0224
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus for and method of generating normalized soft decision information output from an inner decoder (i.e. equalizer) in a communications receiver. The invention is operative to normalize the soft decision information before it enters a soft outer decoder. The normalization is performed using a noise power estimate that is dynamically calculated in response to changing noise statistics on the channel. The normalized soft decision output is then applied to the soft outer decoder thus realizing maximum performance therefrom. The noise power estimate is derived from the training sequence and/or the data portion of the received signal. Both types of estimates are calculated. A binary or smoothly weighted average is calculated using both types of estimates. The weighting factor is determined based on one or more performance metrics, such as the Signal to Noise Ratio (SNR).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.